The invention relates to a processing room for drying or ripening foodstuffs which give off humidity, particularly meat products, which are exposed to a stream of unsaturated air which enters through air inlets distributed over the bottom and is extracted through air outlet orifices at the top.
A processing room of this type is known, for instance, from CH-A-603060. This shows a tunnel-like processing room, the bottom of which is formed by a load bearing coarse grid under which extends the air supply duct. Over the whole arched roof area, the rising air is drawn into a waste air duct and is fed in again under the floor. The floor grid has rails for transporter trolleys on which the material to be processed is moved through the processing room.
Thus, the air is supplied through a plurality of inlet apertures in the floor, so preventing any large-volume eddy formation. Since the supplied air is intended to absorb the water given off by the material being processed, it is unsaturated and hence heavier than the more humid waste air, so that by reason of the differing density, a vertical upwards flow becomes established. The air consequently rises to the roof of the processing room, where it can emerge. The more regularly the supplied air leaves the inlet apertures and, without any dead corners, is able to follow a plurality of parallel flow paths, the higher will be quality of the dried or ripened products.
Different drying rates lead to losses of product quality. For example, in the case of smoked bacon, excessively fast drying leads to a hardening at the edges, while too little ventilation adversely affects the removal of moisture.
It has been found that very low flow speeds (between 0.01 and 0.5 m/sec) provide the best drying results. The flow speed ought thereby to be approximately high enough that the air can just absorb that amount of moisture which an undisturbed capillary movement of water in the material being processed sets free at the surface. The grid floor described in CH-A-603060 is too large-meshed to fulfil the requirement of fine dispersal. However, walking on them would make smaller-mesh grids dirty and clogged, so that the regularity of the air flow would not be guaranteed in this case either.